Mascara and other liquid cosmetics are typically packaged in a bottle having a removable cap and applicator. The applicator is usually mounted to the end of a rod, which is in turn mounted to the inside of the cap. In mascara applications, the applicator is typically a twisted wire brush containing bristles. In other cosmetic applications the applicator may be a cosmetic foam sponge or a felt tip or other absorbent or porous material having a load carrying capacity. The cap is typically threaded and can be screwed onto the neck of the bottle to close the bottle. When the bottle is closed, the rod extends down from the cap through the neck and a wiper element and into the bottle. The cosmetic bulk product, such as mascara, is located in the bottle and the applicator is positioned within the bulk product when the cap is closed. To use the applicator, the consumer will typically unscrew that cap from the bottle and pull the rod and applicator from the bottle. As the rod is withdrawn, it is wiped by the wiper element to remove the bulk product from the rod. The wiper element then wipes the applicator to reduce excess bulk product so that the applicator is loaded with a desirable amount of bulk product which is not too much, and not too little.
Many wiper designs have been developed and used in the past. Typically, the wiper is fabricated of buna rubber or neoprene, which are highly resilient and flexible materials that are both effective and do not degrade during the period of use. However, the material costs and cost of fabrication for wipers made of such materials are relatively high. In addition, wipers fabricated from such materials are not self-seating in the bottle neck, and instead are fabricated as a diaphragm which must be held in place with a separate neck insert, with the diaphragm positioned between insert and the bottle neck.
Wipers have been fabricated from low density polyethylene (“LDPE”), which is a less expensive material to use both in terms of materials cost and fabrication cost. LDPE wipers are relatively rigid and thus provide a poorer seal absent a very thin wiper edge. However, a thin wiper edge is susceptible of a significant potential problem, namely that the rigid wiper edge of the wiper diaphragm will crack and fail through repeated use, causing small bits of broken LDPE wiper to become mixed into the cosmetics bulk product.